Anonymous, 17 Mar 2015only diff is 1,2,3,&4. more ram, tiny processor speed, and wow the same camera*.
*z has 16mp.Z4 will have a new camera sensor, which "should" be improved over the Z1-3 old sensor. What makes photo quality is not only the MP, but rather has a lot to do with the sensor tech and the quality of the optics (lens) used.

The only thing the Z3 really is missing for me is a better quality camera system (lens and sensor).

If the Z4 can make an improvement in photo quality over the Z3 then Sony can take my money.

Of course the SD810 will be welcomed and a slightly larger battery (please don't go backwards like on the S6, thanks)

Anonymous, 17 Mar 2015M9 is burning now.
Z4 running the same SD810... it has to be waterproof. You need to put th... moreShame, you clearly a Sammy fanboy. In that case, live with your rather poor battery life/no sd/non-removable battery S6 ;)

I been having all the Z series since 2013, like the Z,Z1,Z2 and now the Z3. All of them are still at home and not a single one is broken. Get what i mean? It does not break EASILY people. I dont use any bumper or cover casing protection. Just a tempered glass screen protector for the front and normal plastic protector for the glass at the back. I just don't to hide its beauty. I don't know how some people can break their whatever Z's. And i'm a guy. The gender that is renown to be bad at handling items with care..(oh please..)..overall..music is not loud, but super-duper detail and clean if you know how to play with the equalizer, just make sure you know how to get an earphone with low impedance and you will get a loud output. If u need more than that, i just can't say anything but feel sorry for the ears you have..camera..learn how to use manual mode for the 20.7 MP (Z1,Z2 and Z3)..for Z..i have to admit it..it wasn't a good 13MP unit there..but still quite okay. What else you people keep complaining. Battery..okay Z and Z1 is not a good performer. They discharge quick and get too hot at heavy usage. I mean VERY HOT..especially online games. Z2 is good and Z3 is divine. My Z3 lasts for 2 days like what Sony claim. I mean, im suprised too..still..Speed is one of the best around..UI is not laggy towards the newer version..(processor i guess).. Just don't max your phone memory, it will do well..overall, Sony has been giving out good smartphones ever since the Z series emerged. I'm talking with my complete experience here. Just to remove some of your pity thoughts that i might be a fanboy. I have the Samsung Galaxy S4 and Galaxy Note 4 (currently in use along with my Sony Xperia Z3) and the overpriced iPhone 6..XD
They are all excellent phones..Just wanted to tell others that Sony is NOT, okay NOT, as BAD and TERRIBLE as IGNORANT people claimed them to be..hahaha...(sarcasm)..they are doing wonderful products and are actually quite the quality. Just that, people always like to..i don't know..make stupid comparison and YES! it makes people like you look like a total idiot..no offense..

Right..That is my report..Can't wait to taste the Z4..I hope Sony can squeeze that S-Master Audio Chip of them in the Z4..(im an audiophile)..Cheers and have a nice day everyone..:)

ONLY couple of months to wait and don't fall for stupid backwarded Samsung GS6, or Edge, they removed the water resistance of GS5, the most useful spec was water proofing now that is gone...

SONY was the first phone who introduced the water proofing on their top end devices, and now people realise they can't even copy that easy...

Samsung used to be good, but with new releases they have failed.

look at HTC (M9), ! lol same STUPID look, same phone, and now there is a serious bug which everyone will be returning their phone after screen freezes (that is what the problem is they say)

so you seriously think they would resolve that?

lol

as with Samsung GS6, the batter seems to be worse than GS5, and on every charge it gets worse NOT BETTER, so once the batter gets corrupted then pay £200 to Samsung to change the battery for you. it is a joke really. by the way make sure your GS6 don't see a splashes of water because it would simply dies.

Anonymous, 17 Mar 2015When has any phone from Sony been the phone to beat? Please... It will be like the major crap ... morelet me give you an example...
Z3 compact for its size and power it is the best in the market right now, there is nothing out there matching the performance and spec of Z3 COMPACT...NOTHING

and remember there are loads of people who don't like to carry a big phone, so when it comes to compact Z3 still leading the market

so do some reading and understand why SONY can still twist big players arms and lets them bow to superior innovation and reliability of SONY

WhiskeyHotel99, 17 Mar 2015it looks nice but I would never buy another Sony handset, I find them unreliable and have trie... moreSORRY for you... you will miss an outstanding product of one of only THREE manufacturers (apple, nokia, sony) who stand proud for their ORIGINALITY, OUTSTANDING DESIGN & INNOVATION, companies who do not know how to COPY others HAHAHAHAHA...